Geological Chronicle
Located on the far side of the Moon beyond the eastern limb, Lobachevskiy is an impact crater measuring 87.26 kilometers in diameter. Positioned southeast of the larger crater Fleming, with the crater Guyot lying less than a crater diameter to its east-northeast, the formation dates to the Late Imbrian epoch. The crater remains well formed, with physical features that have not been significantly eroded since it first formed.
The rim and inner wall are nearly free of significant overlapping impacts, although the satellite crater Lobachevskiy M is attached to the southern outer rim. The inner walls display terrace features along with some slumping along the upper edge. Near the midpoint of the floor is a pair of central peaks rising to the northwest and southeast, where the infrared spectrum of pure crystalline plagioclase has been identified. To the east of these peaks lies a relatively bright, high-albedo patch, most likely the result of a recent small impact.
During the Apollo 16 mission, observers noted two dark ribbons of material that apparently emanate from the base of a small crater in the western wall. Prior to its formal naming in 1961 after Russian mathematician Nikolai Lobachevsky, the feature was known as Crater 205.